Our overall aim is to acquire information on how the ventromedial hypothalamus participates in the maintenance of caloric balance (i.e., relative constancy of body weight) in animals feeding ad libitum. Our previous work has demonstrated the presence of insulin-dependent glucoreceptor cells in the ventromedial hypothalamus. The glucose analog, gold thioglucose, has provided us with a useful tool for investigating the properties of these cells. We have been able to affect the glucoreceptor cells with a dose of 5 micrograms of gold thioglucose. This is in contrast to our previous method which called for a dose 500 times larger. With the increased specificity of the smaller dose we shall investigate the effect of gold thioglucose-induced neural changes in the ventromedial hypothalamus on blood levels of glucagon, insulin and ketone bodies. We have also found that hypothalamic hyperphagia is dependent on the presence of the adrenal glands; adrenalectomy reduces food intake to normal. This phenomenon is being explored.